Multifocus X-ray sources generally comprise a single anode, typically in a linear or arcuate geometry, that may be irradiated at discrete points along its length by high energy electron beams from a multi-element electron source. Such multifocus X-ray sources can be used in tomographic imaging systems or projection X-ray imaging systems where it is necessary to move the X-ray beam.
When electrons strike the anode they lose some, or all, of their kinetic energy, the majority of which is released as heat. This heat can reduce the target lifetime and it is therefore common to cool the anode. Conventional methods include air cooling, wherein the anode is typically operated at ground potential with heat conduction to ambient through an air cooled heatsink, and a rotating anode, wherein the irradiated point is able to cool as it rotates around before being irradiated once more.
However, there is need for improved anode designs for X-ray tubes that are easy to fabricate while providing enhanced functionality, such as collimation by the anode. There is also need for improved systems for cooling anodes.